A candlelight prayer service is held Saturday night in front of Edmond Town Hall in Newtown, Conn. / Robert Deutsch, USA TODAY

by USA TODAY

by USA TODAY

WASHINGTON (AP) - President Obama will attend a memorial service Sunday in Newtown, Conn., the site of Friday's deadly elementary school shooting.

Twenty-six people, including 20 children, were killed when a man opened fire inside the school.

Hours after the shooting, a tearful Obama said he grieved first as a father. In those remarks and later in his Saturday radio address, Obama called for "meaningful action" to prevent such shootings, but did not say what it should be.

Obama's visit to Newtown for an interfaith vigil would be the fourth time he has traveled to a city after a mass shooting. The vigil is scheduled for 7 p.m.

The president had planned to travel to Maine on Wednesday for an event promoting his positions in "fiscal cliff" negotiations, but the White House canceled that trip because of the shooting.